JVC-QLF6-tt-sm维修电路原理图.pdf

《JVC-QLF6-tt-sm维修电路原理图.pdf》由会员分享，可在线阅读，更多相关《JVC-QLF6-tt-sm维修电路原理图.pdf（27页珍藏版）》请在收音机爱好者资料库上搜索。

1、JVC MODEL taL-Fe QUARTZ FULLY AUTOMATIC TURNTABLE No. 2464 . FEB. 1979 RadioFans.CN 收音机爱 好者资料库 Contents Pages 1. Specifications . 2. ServicePrecautions. Features. 4. NamesofPartsandTheirFunctions. 5. Replacement Procedures (1) Stylus. (2) Headshell .,. (3) Cartridge. . (4) Motor. (5) HO/VODampingKno

2、bs 6 6. Lubrication (1) HO/VODampingMechanism . (2) Motor. (3) FullyAutomaticMechanism. 7. Adjustment Procedures (1) UARTZ LOCK/PITCH CONTROL Meter . (2) OuartzLockAdjustment . 8 Tonearm Section (3) HeadsheliAngle . (4) TonearmElevator. (5) Overhang . (6) Lead-in. (7) Lead-out. (8) TrackingForce. (9

3、) Anti-skating. (10) HO/VODamping . 8. OL-F6BlockDiagram . 9. Troubleshooting Charts (1) Platter does not rotate. . (2) Platter rotates at high speed. . (3) Pitch Control operates abnormally. . 10. Exploded Views and Parts List 10-(1) Cabinet ed oil-damped tonearm : 233 mm : 15 mm : 13 - 20 g 24 g (

4、when using the provided sub-counterweight) 2. Service Precautions . Be sure to use JVC standard parts. . When repairing the speed control circuit board con- nect the m938 G motor in order to prevent damage to the transistor used.in the platter drive section. . Be sure to adjust motor speed with the

5、u nit level otherwise fluctuations which make adjustment impos- sible may occur. . When repairing circuit board with the heat sink re- moved, attach mobile heat-sink to prevent the tran- sistor temperature from rising. CARTRIDGE SECTION (Except for USA, Canada and U. Type : Moving magnet (MD-l025EB)

6、 Frequency response: 10 Hz - 25000 Hz Output : 3 mV (1 kHz) Channel separation: 25 dB (1 kHz) (using the test record TRS- : 47 - 100 k-ohms : 10 x 10 6 cm/dyne (dynamic) 30 x 10 6 cm/dyne (static) : DT-Zl EB, 0.3 x 0.7 mil. (diamond, elliptical) Optimum tracking force: 1.75 g :!: 0.25 g GENERAL Powe

7、r consumption Dimensions Load resistance Compliance Stylus Weight Accessories EP adapter : 15W : Height 14.2 cm (with closed cover) Width 45.6 cm Depth 40.0 cm (Since the dimensions show only the design measurements, con- sideration is requ ired when installing the unit in a limited space such as a

8、rack, etc. : 11 kg (without the packaging) Sub-counterweight : 1 Place the adapter on the center spindle when playing a record having a bigger diameter center hole such as a doughnut record. : 1 Design and specifications subject to change without notice. 3. Features . Newly developed oil-damped tone

9、arm assures high trackability. Highly sensitive, new gimbalsupport tonearm system. . Double-quartz servo circu it and high torque, non- resonance coreless motor give high reliability. . Extra-heavy aluminum diecast platter (2 kg including the mat, inertia 330 kg/cm Howling margin is greatly improved

10、 with the new super-compound (type-l) board used as the base. Operation buttons and controls are positioned at the front for easy operation. . NR-type headshell with minimum resonance is em- ployed. Moving-magnet cartridge with a elliptical stylus. Fine pitch control allows adjustment within:!: 6 %

11、(approx. a half note). . Quartz lock/Pitch control meter for convenient speed check. Fully automatic mechanism. QL- No. 2464 4. Names of Parts and TheirFunctions Mat Dust cover Center spindle Platter Fig. 1 1. OIL DAMPED TONEARM Ordinarily tonearms have a resonance frequency of between 5 to 10Hz. If

12、 the peak of the range of a tonearm is too high, accurate tracking of the tone- arm with the record groove cannot be obtained be- cause the tonearm resonates at a frequency generated by ambient vibrations or sound pressure, or the tone- arm can be influenced by adverse conditions of the record such

13、as warps, etc. The OIL DAMPED TONEARM i designed to suppress the range of resonance by maintaining a low resonant point of the tonearm to prevent howling. With this OIL DAMPED TONEARM, accurate tracking of the record groove as well as a good resistant character- istic to howling is possible, thus re

14、sulting in an im- proveved SIN ratio. I n order to improve the sound quality, the OIL DAMPED TONEARM plays an important role. QL- No. 2464 2. HQ DAMPING knob This controls the horizontal movement of the tone- arm while aiding to keep the tonearms resonating point low. Set the knob to the same indica

15、tion num- ber as the optimum tracking force of this unit. 3. VQ DAMPING knob This controls the vertical movement of the tonearm while aiding to keep the tonearms resonating point low. Set the knob to the same indication number as the optimum tracking force of this unit. 4. Speed select knob Select a

16、 proper position of the speed select knob in accordance with the rpm of the record. 33-1/3 rpm record (LP) . 33 45rpmrecord(EP).45 5. QUARTZ LOCK/PITCH CONTROL select button QUARTZ LOCK: Depress the button to the QUARTZ LOCK position ( ) for playing a record at an accurate rotation speed in the quar

17、tz lock mode. In this case, the meter lights green. PITCH CONTROL: Depress the button a second time to obtain the P ITCH CO NT RO L position (-) in order to per- form fine pitch adjustment for the sound meeting your preference. I n this case, the meter I ights orange. 6. PITCH CONTROL meter When the

18、 QUARTZ LOCK/PITCH CONTROL select button is set to the QUARTZ LOCK position the meter is green-lit and the indicator displays When the QUARTZ LOCK/PITCH CONTROL select button is set to the PITCH CONTROL posi- tion, pitch control can be performed by turning the PITCH CONTROL knob and the meter is ora

19、nge-I it. #6 % means +6 % b6 % means -6 % 7. PITCH CONTROL knob Fine pitch control can be performed with the QUARTZ LOCK/PITCH CONTROL select button set to the PITCH CONTROL position. Pitch adjust- ment range is :!: 6 %. The indicator in the meter deflecting to the left (#) from the center (0) indi-

20、 cates an increase to the accurate 33-1/3 or 45 rpm and the deflection to the right (b) means a decrease. 8. ANTI-SKATING knob This device cancels out the centripetal force that pulls the tonearm to the center of the platter. This prevents the stylus tip from skating toward the center of the platter

21、 and at the same time eliminates any excessive stylus tip force on the inner wall of the record groove. Use the 8 marked dial when em- ploying a spherical stylus. Use the marked dial when employing an elliptical stylus or a SHIBATA stylus. Turn the dial to the same number as on the track ing force d

22、ial. 9. REPEAT knob Decide how many times you want to re-listen to the record by using this knob. When you set the knob to , the record will continue to play repeatedly. Note: This knob cannot be turned to indicate from 1 - 0 or 0 - 1 if the START button is de- pressed with the power cord disconnect

23、ed from the outlet. For this, refer to the note in the section Necessary procedures prior to record playing on page 2. 10. START/REJECT buttons When you start playing a record, depress the ST ART button. The tonearm moves automatically the position of the first groove of the record pre- selected and

24、 gently lowers itself onto the surface of the record to play it. When you stop playing the record, depress the REJECT button. The tonearm lifts, returns automatically to its rest and the platter stops rotating. , however, the REPEAT knob has been set for a number of repeats, the tonearm performs the

25、 cor- respond ing number of prepeats before the platter stops rotating. Note: When the dial of the repeat knob has been set to numbers other than , the platter continues to rotate and the power will not be turned off even though you depress the REJECT button or even if the playing record has finishe

26、d. When you want the power to be turned off after the record has played once, be sure to set the repeat knob to the 0 mark. 11. RECORD SIZE select knob Set the knob to the corresponding position to the size of the record before you play it. 30 cm diameter record. . . . . . . . . . . . 30 (12 25 cm d

27、iameter record. . . . . . . . . . . . 25 (10 17cmdiameterrecord. 17(7) 12. Arm lifter lever This is used when you want to raise the tonearm gently or gently lower it. When you push it to the UP position, the tonearm will be lifted up, and when you pull it to the DOWN position, it will be lowered dow

28、n gently onto the record surface. QL- No. 2464 5. Replacement Procedures 5-( 1) Stylus Stylus replacement (See Fig. 2) Replacement of the stylus can be easily made by simply inserting the stylus plug (A) into the jack (B) of the cartridge. Service life of the stylus employed for this unit (DT-Zl EB)

29、 is generally as follow; varying, depend- ing on the record condition (dirty record groove etc. Stereo LP record (30 cm) . . . Approx. 300 - 500 hours Stylus are disposable items. Therefore, it is recommended to buy a supply of styli when you buy the unit. When purchasing them, specify the DT-Zl EB

30、(JVC standard). 5-(2) Headshell Removal and mounting of the headshell (See Fig. 3) Turn the connector nut in the direction of A to remove the headshell from the tonearm. Turn it in the direction of B for mounting the headshell. 5-(3) Cartridge Mounting the cartridge (See Fig. 4) 1. Remove the 2 scre

31、ws securing the cartridge onto the headshell. 2. I nstall your cartridge onto the headshell provided or onto a headshell of your selection. 3. The headshell lead wires are color-coded as follows connect them correctly. White(+) . L Red(+). BlueH LE Green(- ) ., 4. Mount the cartridge properly onto t

32、he headshell and leave the set screws slightly loosened, then, after completing the Overhang adjustment (See page 9) tighten them firmly. After this adjustment, be sure that the conditions concerning the 3 adjustments on page 5 and 6 are satisfactorily met. 5. After each cartridge replacement, be su

33、re to perform the 4 adjustments described on page 9. (4) Motor How to remove the motor (Fig. 5) Remove the motor in the following sequence. There is no need to remove the mechanisms base. 1. Remove the stopper, main gear and spring attached to the motor plate. 2. Disconnect the plug connecting the m

34、otor with the speed control circuit board. 3. Remove the 4 screws securing the motor. 4. Lift the trip lever as shown in the figure while taking care not to deform it and remove the motor while tilting it. 5. Mount the motor, in the reverse order. QL- No. 2464 Fig. 2 Fig. 3 , s- Cartridge with stylu

35、s Green: to RE or R- of cartridge Blue: to LE or L- of cartridg Red: to R+ or R of cartridge White: to L+ or L of cartrige j Headshell # lift 0 Fig. 4 Fig. (5) HQ/VQ Damping Knobs When replacement of VQ or HQ damping knob becomes necessary, do it in the following sequence. . How to replace the HQ da

36、mping knob (Fig. 6) 1. Remove the 2 screws securing the HQ damping knob and remove the knob. 2. Turn the HQ controller clockwise until it stops. 3. Clamp the tonearm to its rest. 4. Mount the new HQ damping knob on the HQ con- troller with the indication 3 on the knob aligned with the index line. Se

37、cure it with the 2 screws. 5. After replacing it, perform adjustment referring to the section How to use on page 4. . How to replace the VQ damping knob (Fig. 6) Replace in the same way as the HQ damping knob is replaced. 6. Lubrication 6-(1) HQ/VQ Damping Mechanism QL-F6 turntables are completely a

38、djusted at the factory prior to shipment. The damping mechanism cannot be repaired imd it is recommended that it be replaced if it malfunctions. 7. Adjustment Procedures Servo-motor Control Section Ha damping knob Ha controller Index line va controller Fig. 6 Screws t. va damping knob 6-(2) Motor Th

39、e motor needs no lubrication. 6-(3) Fully Automatic Mechanism Apply high quality grease to connecting and sliding parts after they are replaced. 7 -( 1) QUARTZ LOCK/ PITCH CONTROL Meter How to use the QUARTZ LOCK/PITCH CONTROL meter (See Fig. 7- QUARTZ LOCK (): When the QUARTZ LOCK/PITCH CONTROL sel

40、ect button (1) is depressed to tbe QUARTZ LOCK position the meter (2) becomes green-lit. In this mode the rota- tion speed is accurately controlled by phase-locking to the quartz oscillator frequency. This means that correct 33-1/3 or 45 rpm is obtained. The indicator (2) of the meter displays PITCH

41、 CONTROL (-): When performing fine pitch adjustment, depress the QUARTZ LOCK/PITCH CONTROL select button (1) to the PITCH CONTROL position and the meter be- comes orange-lit. In this mode, fine pitch adjustment can be performed by turning the PITCH CONTROL knob (3) within a range of :!: 6 %. Turning

42、 the knob in the (+) direction (counterclockwise) increases the rpm. Turning it in the (-) direction (clockwise) decreases the rpm. The meter indication of +6 % (#) shows the re- produced sound raised by approximately a half tone. Fig. The -6 % (b) indication shows the reproduced sound is lowered by

43、 approximately a half tone. By making these adjustments, record sound reproduc- tion meeting your preference can be obtained. QL- No. 2464 How to make adjustments if the pitch control meter should indicate incorrectly (when the meter does not display 0 in the QUARTZ LOCK operation). (See Fig. 1. Dis

44、connect the power cord from the outlet. 2. Remove the platter from the motor shaft. 3. Turning the 0 position adjusting screw clockwise moves the indication to the right. Turning this screw counterclockwise moves the indi- cation to tl:1e-left. Generally, there is no need for adjustment since proper

45、 adjustment has been performed at the factory. Should the indication of the meter be incorrect adjust it in the manner above. Adjustment of the FINE PITCH CONTROL meter (See Fig. 7- Perform this meter adjustment referring to the items below after making mechanical adjustments pertaining to rpm or repairing the meter circuits. 1. Function of t